CN113391615A - Variable time pulse algorithm for probability statistics - Google Patents

Variable time pulse algorithm for probability statistics Download PDF

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CN113391615A
CN113391615A CN202110506090.1A CN202110506090A CN113391615A CN 113391615 A CN113391615 A CN 113391615A CN 202110506090 A CN202110506090 A CN 202110506090A CN 113391615 A CN113391615 A CN 113391615A
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time
pulse
feedforward
time interval
optimal
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CN113391615B (en
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李珂
刘永红
周小朋
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Northwest Electric Power Research Institute of China Datang Corp Science and Technology Research Institute Co Ltd
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    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05BCONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B23/00Testing or monitoring of control systems or parts thereof
    • G05B23/02Electric testing or monitoring
    • G05B23/0205Electric testing or monitoring by means of a monitoring system capable of detecting and responding to faults
    • G05B23/0218Electric testing or monitoring by means of a monitoring system capable of detecting and responding to faults characterised by the fault detection method dealing with either existing or incipient faults
    • G05B23/0243Electric testing or monitoring by means of a monitoring system capable of detecting and responding to faults characterised by the fault detection method dealing with either existing or incipient faults model based detection method, e.g. first-principles knowledge model
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22STEAM GENERATION
    • F22BMETHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B35/00Control systems for steam boilers
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05BCONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B2219/00Program-control systems
    • G05B2219/20Pc systems
    • G05B2219/24Pc safety
    • G05B2219/24065Real time diagnostics

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of Steam Boilers And Waste-Gas Boilers (AREA)

Abstract

The invention discloses a variable time pulse algorithm of probability statistics, which is used for carrying out optimization calculation on a pulse time function block in a main control optimization method of a stop-grinding pre-judging boiler based on the probability statistics.

Description

Variable time pulse algorithm for probability statistics
Technical Field
The invention belongs to the technical field of boiler control, and relates to a variable time pulse algorithm for probability statistics.
Background
In the process of frequent change of the load of the thermal power generating unit, when the AGC instruction of a power grid side requires load reduction of the thermal power generating unit, along with reduction of the load of the unit, when the load of the unit is reduced to a working condition that the grinding unit needs to be stopped, firstly, the coal feeding rate of a coal feeder of the grinding unit is reduced in a step-type manner at a certain speed from the current coal feeding rate, after the coal feeding rate of the coal feeder is reduced to the grinding unit stop buffer coal feeding rate, the coal feeding rate of the coal feeder is kept to continue to operate for about 1min under the working condition of the grinding unit stop buffer coal feeding rate, the coal feeding rate of the coal feeder is reduced to 0t/h, and then the coal feeder is stopped. After the coal feeder stops running, the coal mill and a hot primary air door of the coal mill are stopped and closed after delaying for about 2min, so that all pulverized coal cached in the inertia of the coal mill is ensured to be blown into a hearth, the occurrence of deflagration accidents caused by coal accumulation when a next grinding group is started is prevented, but the pulverized coal cached in the inertia of the coal mill enters the hearth to be combusted, the main steam pressure is directly increased in the load reduction process and even exceeds the safety value of the main steam pressure, and the safety and the stable running of a unit are seriously influenced.
The method comprises the steps of researching the grinding process and rule of operators by grinding stop and prejudgment boiler master control feedforward of probability statistics, abstracting the grinding stop and prejudgment boiler master control feedforward of probability statistics, and combining the change of main steam pressure deviation to dynamically adjust the amplitude, zero return time and zero return rate of the grinding stop and prejudgment boiler master control feedforward of probability statistics in real time, thereby comprehensively adjusting the change of main steam pressure in the load reduction grinding process.
In the stop-run pre-judging boiler main control feedforward optimization method based on probability statistics, the setting of pulse time plays a crucial role in the optimization effect, a variable-time pulse algorithm system based on probability statistics comprehensively calculates the optimal pulse time of a pulse function block in stop-run pre-judging boiler main control feedforward through the ideas of big data acquisition, data classification and probability statistics, fundamentally ensures the magnitude effect of the feedforward magnitude effect, and avoids the problem that the feedforward magnitude effect cannot meet the actual requirement of the system due to the change of the system working condition.
Disclosure of Invention
The invention aims to provide a variable time pulse algorithm for probability statistics, which solves the problem that the effect of feedforward quantity value action cannot meet the actual requirement of a system due to the change of the working condition of the system in the prior art.
The technical scheme adopted by the invention is that a variable time pulse algorithm of probability statistics is implemented according to the following steps:
step 1, data acquisition: defining a circle as a period, and acquiring a pulse time value t in each feedforward triggering process according to the periodnAnd the maximum value P of the absolute value of the deviation between the main steam pressure set value and the main steam pressure measured value in the time period from the feed-forward trigger to the feed-forward zero-returningmax
Step 2, data statistics: counting the statistics of each of all the equidistant sections in one periodFeedforward trigger times deltan
Step 3, data screening and calculation: according to deltanAnd PmaxAveraging T of pulse times within an optimal time intervalAre all made ofI.e. as the optimum pulse trigger time for the next cycle.
The invention is also characterized in that:
collecting the pulse time value t in each feedforward triggering processnThe method comprises the following specific steps:
step a, dividing the total pulse triggering time interval into n equidistant intervals, wherein the interval time of the equidistant intervals is the same, and obtaining n pulse time values t after each feedforward triggeringn
B, using set to calculate the pulse time t in each feedforward triggering processnAnd (4) showing.
The total pulse triggering time interval of the step a is 120 s-180 s, the number n of equidistant intervals is 6, and the 6 equidistant intervals are t1、t2、t3、t4、t5、t6Equidistant intervals are 10s apart.
The set of steps b is:
Figure BDA0003058443360000032
step 3 is specifically implemented according to the following steps:
step 3.1, determining an optimal time interval;
step 3.2, marking the pulse triggering times delta in the optimal time intervaln0Calculating the time sum t 'of all trigger pulses in the optimal time interval'nAs shown in formula (2):
Figure BDA0003058443360000031
step 3.3, solving the average value T of the pulse time in the optimal time intervalAre all made ofAs shown in formula (3):
Tare all made of=t’nn0 (3)
For deltanAfter sorting according to the sequence from big to small, taking deltanMaximum and maximum value P of the absolute value of the deviation between the steam pressure set value and the main steam pressure measured valuemaxThe time interval within | + -0.3 Mpa is the optimal time interval.
The invention has the beneficial effects that:
1. the method carries out optimization calculation on the pulse time function block in the main control optimization method of the boiler based on the probability statistics and the stop-grinding prejudgment.
2. The invention comprehensively calculates the optimal pulse time of the pulse function block in the main control feed-forward logic of the boiler for wear-stopping prejudgment through the ideas of big data acquisition, data classification and probability statistics,
3. the invention fundamentally ensures the magnitude effect of the feedforward magnitude action and avoids the problem that the feedforward magnitude action effect cannot meet the actual requirement of the system due to the change of the working condition of the system.
Detailed Description
The present invention will be described in detail with reference to the following embodiments.
Example 1
The invention relates to a variable time pulse algorithm for probability statistics, which is implemented by the following steps:
step 1, data acquisition: defining one cycle as a time period, feeding forward the minimum time t of trigger pulse in the first cycle of embodiment 1min121s, maximum value tmax178s, the total interval of pulse trigger time is 120-180 s based on the division, and the interval is divided into 6 equidistant intervals t1、t2、t3、t4、t5、t6Each interval is 10s, and the pulse time value t in each feedforward triggering process is integratednRepresented by formula (1):
Figure BDA0003058443360000041
step 2, counting each of 6 equidistant intervals in a periodNumber of successful pulse triggers δ1、δ2、δ3、δ4、δ5、δ6
Step 3.1, data screening and calculation: for delta1、δ2、δ3、δ4、δ5、δ6After sorting according to the order from big to small, the maximum delta is takennAnd the maximum value P of the absolute value of the deviation between the set value of the steam pressure and the measured value of the main steam pressuremaxThe time interval within | + -0.3 Mpa is the optimal time interval.
Step 3.2, marking the pulse triggering times delta in the optimal time intervaln0Calculating the time sum t 'of all trigger pulses in the optimal time interval'nAs shown in formula (2):
Figure BDA0003058443360000051
step 3.3, solving the average value T of the pulse time in the optimal time intervalAre all made ofAs shown in formula (3):
Tare all made of=t’nn0 (3)
And 4, returning data: mean value T of the pulse time in the optimum time intervalAre all made ofFor optimal pulse time in the current period, the time average value TAre all made ofAnd inputting the time-variable pulse block TP to dynamically optimize the time parameter.
And 5, data analysis: and analyzing the abnormal interval (the pulse triggering time is less than or equal to 3 times or the maximum value of the absolute deviation value between the main steam pressure set value and the main steam pressure measured value is greater than 1.0 MPa) to provide a basis for judging whether the coal mill and the coal feeder have abnormal working condition points such as equipment body faults, whether the operation of operators is appropriate, whether the coal quality is violent in fluctuation and the like.

Claims (6)

1. A variable time pulse algorithm of probability statistics is characterized by being implemented according to the following steps:
step 1, data acquisition: define oneThe period is one period, and the pulse time value t in each feedforward triggering process is acquired according to the periodnAnd the maximum value P of the absolute value of the deviation of the main steam pressure in the time period from the feedforward trigger starting to the feedforward zero returningmax
Step 2, data statistics: counting the successful times delta of feedforward triggering in all equidistant sections in one periodn
Step 3, data screening and calculation: according to said deltanAnd PmaxAveraging T of pulse times within an optimal time intervalAre all made ofI.e. as the optimal pulse trigger time in the next cycle.
2. The probabilistic statistical time-varying pulse algorithm of claim 1, wherein the pulse time t is collected for each feedforward triggernThe method comprises the following specific steps:
step a, dividing the total pulse triggering time interval into n equidistant intervals, wherein the interval time of the equidistant intervals is the same, and obtaining n pulse time values t after each feedforward triggeringn
B, using set to calculate the pulse time t in each feedforward triggering processnAnd (4) showing.
3. The probabilistic variable time pulse algorithm according to claim 2, wherein the total pulse trigger time interval of step a is 120s to 180s, the number of equidistant intervals N is 6, and 6 of the equidistant intervals t is1、t2、t3、t4、t5、t6Equidistant intervals are 10s apart.
4. A probabilistic statistical time-varying pulse algorithm according to claim 3, wherein the set of steps b is:
Figure FDA0003058443350000011
Figure FDA0003058443350000021
5. the probabilistic statistical time-varying pulse algorithm according to claim 1, wherein the step 3 is specifically implemented according to the following steps:
step 3.1, determining an optimal time interval;
step 3.2, marking the pulse triggering times delta in the optimal time intervaln0Calculating the time sum t 'of all trigger pulses in the optimal time interval'nAs shown in formula (2):
Figure FDA0003058443350000022
step 3.3, solving the average value T of the pulse time in the optimal time intervalAre all made ofAs shown in formula (3):
Tare all made of=t′nn0 (3)
6. A probabilistic statistical time-varying pulse algorithm as in claim 5, wherein δ is a pairnAfter sorting according to the order from big to small, the maximum delta is takennAnd the maximum value P of the absolute value of the deviation between the set value of the steam pressure and the measured value of the main steam pressuremaxThe time interval within | + -0.3 Mpa is the optimal time interval.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114637464A (en) * 2022-02-24 2022-06-17 中国大唐集团科学技术研究院有限公司西北电力试验研究院 Flexibly-controlled ten-minute periodic timing and data storage method

Citations (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005299955A (en) * 2004-04-07 2005-10-27 Toshiba Corp Boiler controller
US20060191896A1 (en) * 2005-02-14 2006-08-31 Emerson Process Management Power & Water Solutions, Inc. Method and apparatus for improving steam temperature control
CN101509656A (en) * 2008-12-17 2009-08-19 中国电力科学研究院 Supercritical DC furnace synthesis type coordinating control method
JP2009300038A (en) * 2008-06-16 2009-12-24 Babcock Hitachi Kk Boiler controller and boiler control method
KR20100048487A (en) * 2008-10-31 2010-05-11 한국전력공사 Control method for fast and stable load control by compensating turbine and boiler response delays in power plants
JP2011100203A (en) * 2009-11-04 2011-05-19 Fuji Electric Systems Co Ltd Position control device
CN103499102A (en) * 2013-09-29 2014-01-08 国家电网公司 Method for directional control over quantity of fuel entering boiler of thermal generator set
JP2014115227A (en) * 2012-12-11 2014-06-26 Taisei Corp Method of computing feedforward control force
CN106123005A (en) * 2016-06-23 2016-11-16 国网新疆电力公司电力科学研究院 The coal-supplying amount pre-control method of coal unit boiler feed-forward
CN106382615A (en) * 2016-08-25 2017-02-08 西安西热控制技术有限公司 Verification system and method for ultra-supercritical unit multi-time reheat steam temperature control strategy
CN107168062A (en) * 2017-05-31 2017-09-15 国网河南省电力公司电力科学研究院 A kind of load forecasting method in supercritical coal-fired units coordinated control system
JP6278543B1 (en) * 2017-02-17 2018-02-14 三菱日立パワーシステムズインダストリー株式会社 Coordinated control operation device for fluidized bed boiler power generation system
US20180058248A1 (en) * 2016-08-31 2018-03-01 General Electric Technology Gmbh Advanced Startup Counter Module For A Valve And Actuator Monitoring System
CN108088558A (en) * 2016-11-21 2018-05-29 阿自倍尔株式会社 Flame detector system
CN110486749A (en) * 2019-08-29 2019-11-22 国网河南省电力公司电力科学研究院 A kind of thermal power unit boiler optimized control method of combustion and system
CN111367226A (en) * 2020-04-08 2020-07-03 中国大唐集团科学技术研究院有限公司西北电力试验研究院 Boiler master control feedforward control method based on wear-stopping prejudgment
CN111830831A (en) * 2020-07-23 2020-10-27 天津国电津能滨海热电有限公司 Control optimization method and control optimization system applying multi-term self-adaptive dynamic feedforward
CN111853848A (en) * 2020-06-29 2020-10-30 东北电力大学 Optimization method for fuel quantity distribution among different-layer combustors of coal-fired boiler
CN112286057A (en) * 2020-11-03 2021-01-29 内蒙古电力(集团)有限责任公司内蒙古电力科学研究院分公司 Coal amount optimizing and predicting control method based on AGC optimization of thermal power plant
CN112394651A (en) * 2020-10-16 2021-02-23 华电电力科学研究院有限公司 Main control feed-forward method for temperature-reducing water boiler of thermal power generating unit

Patent Citations (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005299955A (en) * 2004-04-07 2005-10-27 Toshiba Corp Boiler controller
US20060191896A1 (en) * 2005-02-14 2006-08-31 Emerson Process Management Power & Water Solutions, Inc. Method and apparatus for improving steam temperature control
JP2009300038A (en) * 2008-06-16 2009-12-24 Babcock Hitachi Kk Boiler controller and boiler control method
KR20100048487A (en) * 2008-10-31 2010-05-11 한국전력공사 Control method for fast and stable load control by compensating turbine and boiler response delays in power plants
CN101509656A (en) * 2008-12-17 2009-08-19 中国电力科学研究院 Supercritical DC furnace synthesis type coordinating control method
JP2011100203A (en) * 2009-11-04 2011-05-19 Fuji Electric Systems Co Ltd Position control device
JP2014115227A (en) * 2012-12-11 2014-06-26 Taisei Corp Method of computing feedforward control force
CN103499102A (en) * 2013-09-29 2014-01-08 国家电网公司 Method for directional control over quantity of fuel entering boiler of thermal generator set
CN106123005A (en) * 2016-06-23 2016-11-16 国网新疆电力公司电力科学研究院 The coal-supplying amount pre-control method of coal unit boiler feed-forward
CN106382615A (en) * 2016-08-25 2017-02-08 西安西热控制技术有限公司 Verification system and method for ultra-supercritical unit multi-time reheat steam temperature control strategy
US20180058248A1 (en) * 2016-08-31 2018-03-01 General Electric Technology Gmbh Advanced Startup Counter Module For A Valve And Actuator Monitoring System
CN108088558A (en) * 2016-11-21 2018-05-29 阿自倍尔株式会社 Flame detector system
JP6278543B1 (en) * 2017-02-17 2018-02-14 三菱日立パワーシステムズインダストリー株式会社 Coordinated control operation device for fluidized bed boiler power generation system
CN107168062A (en) * 2017-05-31 2017-09-15 国网河南省电力公司电力科学研究院 A kind of load forecasting method in supercritical coal-fired units coordinated control system
CN110486749A (en) * 2019-08-29 2019-11-22 国网河南省电力公司电力科学研究院 A kind of thermal power unit boiler optimized control method of combustion and system
CN111367226A (en) * 2020-04-08 2020-07-03 中国大唐集团科学技术研究院有限公司西北电力试验研究院 Boiler master control feedforward control method based on wear-stopping prejudgment
CN111853848A (en) * 2020-06-29 2020-10-30 东北电力大学 Optimization method for fuel quantity distribution among different-layer combustors of coal-fired boiler
CN111830831A (en) * 2020-07-23 2020-10-27 天津国电津能滨海热电有限公司 Control optimization method and control optimization system applying multi-term self-adaptive dynamic feedforward
CN112394651A (en) * 2020-10-16 2021-02-23 华电电力科学研究院有限公司 Main control feed-forward method for temperature-reducing water boiler of thermal power generating unit
CN112286057A (en) * 2020-11-03 2021-01-29 内蒙古电力(集团)有限责任公司内蒙古电力科学研究院分公司 Coal amount optimizing and predicting control method based on AGC optimization of thermal power plant

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
YUKUN DING: ""Optimizing Boiler Control in Real-Time with Machine Learning for Sustainability"", 《INDUSTRY AND CASE STUDY PAPER》, 31 December 2018 (2018-12-31), pages 2147 - 2154 *
张卫庆: ""基于前馈策略的燃气锅炉负压控制优化"", 《江苏电机工程》, vol. 30, no. 3, 31 May 2011 (2011-05-31), pages 72 - 73 *
朱林忠 等: ""锅炉一次风量及磨煤机启停控制改进"", 《热力发电》, 31 December 2002 (2002-12-31), pages 49 - 51 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114637464A (en) * 2022-02-24 2022-06-17 中国大唐集团科学技术研究院有限公司西北电力试验研究院 Flexibly-controlled ten-minute periodic timing and data storage method
CN114637464B (en) * 2022-02-24 2024-05-14 中国大唐集团科学技术研究院有限公司西北电力试验研究院 Flexibly-controlled ten-clock staged timing and data storage method

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